| Título: | Solution properties of self-assembling azo aromatic polymers |
| Autores: | Norman, Lana Laurette |
| Fecha: | 2003 |
| Publicador: | McGill University |
| Fuente: |
Ver documento |
| Tipo: | Electronic Thesis or Dissertation |
| Tema: | Chemistry - Organic |
| Descripción: | Amphiphilic copolymers of hydrophobic Disperse Red 1 acrylate (DR1A) and hydrophilic acrylic acid (AA) were dissolved in THF and a H2O/THF co-solvent series. The thermal cis-trans isomerization behavior of the azo groups was measured by means of flash photolysis to investigate self-assembled structure in solution. The rate constants observed for the azo-containing polymers permit an estimation of how the thermal isomerization is influenced by both polymer and solution properties. In pure THF the relaxation can be analyzed by a monoexponential decay. In aqueous-organic solutions all poly(DRlA-co-AA) samples show a slow isomerization process due to inhibited mobility of the azo groups, preceded by a faster isomerization process for unaggregated azo groups. In such cases, the relaxation of the cz's-isomer was fit to a biexponential function which clearly demonstrates two distinct local chromophore environments. The spectroscopic results of this study suggest that weakly aggregated states of the amphiphilic polymers in an aqueous-organic solution can be readily studied through isomerization spectroscopy to estimate the fractions of aggregated groups involved and their local environment. |
| Idioma: | en |
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